Documentation for Experimenters

Updated: May 2009

This document explains how Experimenters can use the Momentum^TM software to accomplish the scheduling of subjects and the awarding of research credits.  Additional explanations and instructions are available on the website when you attempt to perform many of the procedures described below. 

Experimenter area of the website

To post an experiment, check the schedule, or award credits, and for all experiment bookkeeping you should enter the research participation web site the same way that all of your participants enter the site.  This will be an address of the form http://experimetrix.com/myuniv where "myuniv" is the selected abbreviation of your university.  Next, select "experimenter.area" from the menu (depending on your customized settings, the exact wording of this link may differ).  You will be asked for a logon and password.  Your logon is the experiment number.  Use the password that your administrator gave you.  (Your department administrator will assign you an experiment number and a password.)

Quick start

For those of you who can't stand reading documentation, here's all you need to get started quickly:

1.  Get an experiment number and password from your administrator

2.  Select "experimenter area" from the main page.  Your logon is the experiment number.  Use the password that your administrator gave you.

3.  Select "edit header" to provide details for your experiment posting.

4.  Select "add new times" to add sessions that people can sign up for.

5.  Select "view schedule" to look at the current schedule and be sure to check the box labeled "Display experiment to students".  (You may need to select a view that lists at least one session in order to see the "display experiment to students" checkbox.)

6.  After the experimental session, select "view schedule" to award credit (or penalty) to the participant.

Slower start

Listed below are most of the things that you can do as an experimenter.  These options can each be selected after logging in to the experimenter area.  For specific situations, also see the Common scenarios section below.

View Schedule  (This is the option typically used for awarding credit for past sessions)

This option displays the schedule for your experiment.  A drop-down list provides several filters that you can use to show specified subsets of the sessions in your experiment.  You can see past sessions, future sessions that are taken (i.e., for which a participant has signed up), and available future sessions.  For any past sessions you have the option of awarding research credit, applying the penalty (for the participant  failing to show up for an appointment), or canceling the session and removing it from the schedule all together (with no credit or penalty).  Each of these options has help associated with it which you can access by clicking the symbol.  Future sessions can be removed from the schedule from this area also.  Note that on this screen the participant names are links that permit you to send email to them (if you are using a browser that is properly configured to do so).  Note also that changes that involve cancellation of a session will produce an email message that is sent to the participant informing them of the cancellation (if your administrator has that option activated, and if the cancelled session is in the future).

The check box "Display Experiment to Students" at the top of this page can be used to either display (when checked) or hide the experiment from students.  If the box is checked the experiment will be visible to students only if there are future sessions in the schedule.  (There is no need to display an experiment if there is no scheduled or possible future activity!)  If the box is not checked the experiment will not be seen by subjects who are looking for an experiment in which to participate.  (You may need to select a filter that produces a list of at least one session before you will see the "display experiment to students" checkbox.)

Add New Times
This is the option to choose if you want to create new sessions in your experiment.  You can pick a date and time for the session, and you can add multiple sessions all at the same time.  By default, a session is an "open appointment" in the sense that it will be an available time for which a student might sign up.  However, it is also possible to sign up on behalf of a specific student when you create the appointment.  For example, you might have ascertained through a telephone call that a particular student is able to participate in your experiment at a specific time.  You can simply create that time slot for them and add them right to the schedule as you are creating it.  To do this, specify the date and time, and in the "participant" box, select the participant who you would like to schedule.  Note that only registered members who have activated their account (that is, logged on within 3 days of receiving their password) will appear as a potential choice in the participant box.

If you do plan to add a participant directly to the schedule, we suggest that you do so as soon as possible after having agreed on an appointment time.  This will help prevent possible future scheduling conflicts.  We urge you to NOT use this option to create "phantom" appointments for participants who are not expected to attend an actual session.  Instead, use batch credit or direct credit to award credit to a participant who has not signed up for an appointment.

View Reports:  This option provides comprehensive, exportable tables that list details about your past and future experiment participants.  The tables can be sorted based on features such as student name, appointment time, and credit amount. 

Batch Credit
This is a way to award credit to students who have participated in your experiment but who did so without having signed up for an appointment.  (If the subject signed up for an appointment, credit should be awarded to them through the "view schedule" page, as described above.)  This feature may be useful if you conduct "batch testing sessions" or other situations in which people participate in your experiment without having signed up through the web site.  In these situations you should obtain the student ID numbers of the participants.  (If you do not have the student ID numbers, then you can assign credits using the direct credit option described below.)

The student ID numbers can be typed directly or pasted into the box on the batch credit page.  The batch credit page provides additional information about this option.  Note that any ID numbers that the software does not recognize (if, for example, a student has not yet registered and activated their account) will be displayed to you after you submit the numbers.  So, you can be confident that the credit has actually been awarded unless you receive a message to the contrary.

Direct Credit
You can use direct credit to award credit to a student who participated in your experiment but who did so without having signed up for an appointment.  (If the subject signed up for an appointment, credit should be awarded to them through the "view schedule" page, as described above.)  Here you need the participant's name, but not their ID number.  (If you have only their ID number, use batch credit, described above.)  The procedure is very simple--select the option from the experimenter page to see more details.  (If you have a large number of participants to be awarded credit you may find that the batch credit option is more convenient to use than direct credit.)

Edit Header
This may be the first thing you will need to do--but then you may never need to do it again.   The header contains the description of your experiment that is displayed to potential participants when they are searching for an experiment in which to participate.  The information required is straightforward.  A subset of the information is shown on the "sign up" page that contains the listing of all current experiments.  The remaining information from the header is visible when the participant selects "view schedule".

Feature: It is possible to prevent students who are browsing for an experiment from seeing the appointments that have already been made by other students.  To do this check the box on the "edit header" page labeled "Only show available sessions in public schedule.".  When checked, a student browsing for an appointment will only see the available time slots.

Web experiments: It is possible to force your experiment to appear in the experiment list even if there are no future sessions.  To do so, check the box labeled "web experiment".  This is useful if you want members to use some sort of unscheduled resource such as a survey or experiment that is on a web page.

Web experiment login and tracking. A new option is available for web experiments. With this option a student must first provide a logon and password before they will be given the URL to your web experiment. If you enable this feature you can ensure that students who are directed to your web experiment are registered members in the system. Furthermore, the system will check to enforce any eligibility requirements associated with your experiment. Finally, when students 'sign up' for this type of experiment an appointment is automativally inserted into your experiment schedule with a time equal to the time of the signup, and a status of 'pending'. You can thus easily assign credits to studnets the way you would for a regular experiment.

You can now specify if students can potentially receive payment for participation in your experiment instead of credit. If you select "Students can be paid for participation" a new option will appear when it is time to award a session credit or penalty. The option will allow you to designate a payment amount and also an account or reference number. You may award credit, as usual, or you can designate that the participant received payment. Participants who are awarded payment will be treated by the eligibility-testing routines as if they have participated in your experiment, even though they will have earned zero credit units for their participation. Importantly, the payment amount and account or reference number for each session will also be available in "member activity reports" that your administrator can produce, perhaps for the purpose of tracking the payments.

View Past Sessions
You can see sessions from past terms if your administrator has indicated that such information should be saved. 

Change Password
You can change the password for your experiment.  Select this option to do so.

Set Eligibility
You can restrict participation in your experiment to students who have not been in certain specific other experiments, or to participants who have participated in other "prerequisite" experiments.  Do so by selecting this option.  By default, students are not permitted to participate in your experiment more than once, and participation in any other experiment has no bearing on eligibility for the current experiment.  The instructions on the page are easy to follow.  (You can also constrain eligibility on the basis of the prescreening survey.  See the section below for details.)

Prescreening Survey Response Selector
  With this option, if prescreening surveys are enabled on your site, you can specify the particular responses that are required in order for a member to be eligible to sign up for your experiment.  For any question in the survey you may choose to "Ignore" the question, or you can select any or all of the potential responses as acceptable responses.  Members will be permitted to sign up for your experiment only if they have responded with one of the responses that you have designated.  Members who are not eligible will be told simply that their prescreening responses render them ineligible for your experiment--they are not told specifically which response(s) is the critical one.

The eligibility tests are enforced only when a member is signing up for your experiment by browsing through the experiment listing.  If you add a new eligibility requirement, there may be some members who have previously signed up for future appointments--these appointments will NOT be deleted.  Also, the eligibility test will not be conducted when you add a  member directly to the schedule, or when you award direct credit or batch credit in your experiment.

Set Authorization Code
You can use this option to restrict sign ups for your experiment.  If you enter a value for "Authorization Code" on this page participants will be required to provide the code when they sign up for your experiment. This can be useful if you wish to restrict potential participants based on some known criterion.  For example, if you previously performed mass testing and wish only to allow people who attained a particular score to participate in your experiment you could set an authorization code for your experiment and then provide that code only to people who meet your eligibility criteria, perhaps with a mass e-mailing. Then if they decide to participate they can sign up for times you have posted, but no one else can.

Set Lead Time
With this option you can prevent participants from signing up at the last minute, perhaps catching you unprepared to conduct the experiment on short notice.  On this page you can specify a "lead time" (in days, hours, and minutes).  Any open appointments that are not taken within that lead time of the scheduled start time will be automatically removed from the schedule.  If a subject cancels within the lead time, their time slot will disappear from the schedule.  Note that the lead time is not the same as the minimum time needed for a participant to cancel.  That time is set by your administrator.

Common scenarios facing experimenters:

How do I make my experiment visible in the listings?

For an experiment to be visible (1) there must be some future appointment times, either open or taken, AND (2) in the "view schedule" option from the experimenter page you must check the box "Display experiment to students".  

How do I create a session for a particular participant?

Select "add new times" from the experimenter page.  Select the date for the session and the start and stop times.  In the "participant" box, select the participant who you would like to schedule.  Click "add new times".  (Only participants who have registered and activated their accounts will be available to choose from.  Accounts are activated when the participant logs on within 3 days of registration.)

How do I cancel a session for a participant who phoned-in to cancel?

Assuming that the participant called soon enough to cancel without penalty, you can cancel their session from the "view schedule" page.  Find the session in question and press the "cancel" button.  All records of the appointment will be removed--the effect will be as if the participant had never signed up for the experiment.

How do I award credit to a participant who served in an experiment "off the books" (i.e. someone who served but did not sign up through the web site)

If you know the participant's ID number: use "batch credit".
If you know the participant's name use "direct credit".
(Either method will be effective only for participants who have registered and activated their accounts.  Accounts are activated when the participant logs on within 3 days of registration.)

We urge you NOT to create "phantom" sessions for participants if you do not expect them to actually attend.  One reason is that creation and cancellation of such sessions often results in email to the participant reminding them of their "appointment", many of whom will forget that it was not to be a "real" appointment.  Instead, batch credit, or direct credit should be used.

How do I remove my experiment from the listings?

Go to the "view schedule" page.  Clear the checkbox marked "Display experiment to students". 

How do I award extra credit for a session that was longer than expected?

Depending on the rules governing the use of your participant pool, you may have the option of awarding  a participant a number of credit units other than the default for your experiment.  When credits are awarded from the "view schedule" page, a box is available in which the number of credits can be entered.  The default value for your experiment is set on the "edit header" page.

How can I restrict signups to certain people who qualified based on some external criterion?

If you have a subset of participants who are eligible for your experiment perhaps because of some score they obtained on some test, or because they are enrolled in a particular course, you may set an authorization code for your experiment.  The code might be announced in class (if all present are eligible), sent via email, or delivered via telephone.  In any case, the scheduling software will handle the details of scheduling the appointments, and you can be assured that only members who know the authorization code will be able to sign up.  An alternative to the authorization code is to credit all eligible students with zero credits in a "screening experiment".  (The zero credits will not affect their credit total.)  Then select "set eligibility" and make participation in that screening experiment a requirement for participation in your experiment.

How can I schedule a multi-session experiment?

One way to do this is to use two experiment numbers--one for the first session and one for the second session.  Participants can be informed (perhaps through the experiment description in the experiment header) that both sessions must be scheduled to receive credit.  After having served and received credit for the first session, subjects can be asked to sign up for the second.  Importantly, the eligibility for the second "experiment" (session) can be set to require participants to have completed the earlier experiment.

What if my experiment meets in different places on different days?

The easiest way to deal with this is to use unique experiment numbers for each location of your experiment.  Eligibility can be set so that no student can sign up for any one of the experiments if they had been in any of the others.  Using unique experiments for each location can help to eliminate confusion regarding the testing location.

What if you need help?

If you have questions, you should contact your department administrator.  (Usually the person who provided you with an experiment number and password.)  You can reach them through most pages on the web site via a link at the bottom of the page.